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Stew
07-05-2006, 01:42 AM
I am just starting to play with a newly hacked HR10-250.
My goal is to stream HD content over the Internet.

First, thanks to Jamie for resolving my problem with killhdinitrd
vs. the 3.1.5e kernel; networked access to TiVo is now working.

Also, thanks for porting netperf to the TiVo MIPS environment.
Unfortunately, using the same 128 kB socket/message size as in your
example, I get only ~18 Mbps when one tuner is recording HD (~22 Mbps
with neither tuner active). I believe that I need to improve network
performance by about 50% to have a decent operating margin. Is that a
reasonable estimate?

My present setup uses a Netgear FA120 (claimed to be same chip as
Linksys USB 200M), connected via a cross-over cable to a 82547EI
1000BaseT Ethernet NIC on the server motherboard; there is a second
NIC that connects the server to the Internet.

Is it possible to get the needed improvement using this hardware,
e.g. by parameter changes, better drivers, different kernel, etc? If
not, should I get a USB to gigabit Ethernet device (which one?), or a
USB-to-USB cable?

The present config is: stock 3.1.5 kernel, TiVo-supplied usbcore.o,
ehci-hcd.o and ax8817.o, all loaded with no special options.
I tried to increase the MTU on eth0 with ifconfig, but get
SIOCSIFMTU: Invalid argument
errors (the command does let me set values less than 1500).

Once I get adequate network throughput, the next problem is how to
stream content from TiVo to server. Do any of the daemons (vserver,
mfs_ftp, etc.) have a way to follow a growing recording and avoid
running past the end? If not, what do you suggest is a good package
in which to implement this feature?

Finally, I have a question somewhat off-topic for this forum, but I
believe that some experts here can offer good advice: how should the
stream be transcoded? My present upload speed is ~5 Mbps (wireless)
at the source location; ~15 Mbps download (ADSL2+) at the destination.
I've seen good-looking H.264 and WMV9 content at 5 Mbps, but I don't
see any way to transcode to those formats in real time at reasonable
cost. Upgrading both Internet connections to ~20 Mbps to handle the
raw MPEG-2 stream would also be quite expensive, though improving
source end upload speed to ~10 Mbps is practical. It appears that the
only plausible solution is to select a less aggressive (8 to 10 Mbps?)
but less computationally intensive compression scheme (some MPEG-4
variant?) that will work in real time, with a new server motherboard
and CPU(s) if needed. What format/encoder/platform/hardware is
recommended for streaming HD? I see nothing about that on the forums;
surely I'm not the only one trying to do it.

Thanks in advance for suggestions on any facet of this problem.

cognac
07-10-2006, 03:08 PM
I do a little dabbling in TiVo streaming my self. I haven’t done it directly over the Ethernet connection of the TiVo but rather from the video/audio output jacks on the back of the TiVo. Direct HD broadcasting will take a lot of bandwidth. You would need a backbone connection to the phone company. So far as I know there is no compressor for streaming HD directly over the internet, only SD. What I use on my system is a firewire digital/analog video capture-converter, like a Synchrotech DAC-200 or a Dazzle from Pinnacle systems. I have a firewire model from Dazzle before Pinnacle systems bought them out. Using the IEEE-1394 firewire or USB connection from the output of the video converter connect to the PC or rather a Mac Dual G5 in my case. PC will work as well. For simplicity I use Apples QuickTime Broadcaster and Streaming Server, both are free downloads. Microsoft’s media player, RealPlayer and VLC also do streaming as well and VLC is available for the OS X, Windows and Linux OS. What is nice about QuickTime Broadcaster is that the compression to either H.264 or mpeg4 is on the fly. That is to say it doesn’t have to save a file then broadcast like the others do using disk space. You can use a QuickTime plug-in in your webpage or pick it up directly with QuickTime player its self using rtsp protocol from open url. Setup is easy and low cost. If you want to see my live TiVo feed online PM me for the link. I hope this helps.

Cognac